Mobile shelving carriage



Feb. 11, 1969 STALLER 3,427,085

- MOBILE SHELVING CARRIAGE Filed April 26, 1967 Sheet Of 2 INVENTOR I /at a 4/ W23 ,l,3s

Iv -Arlee E $75440 ITORNEY 1969 M. F. STALLER j 3,427,035

MOBILE SHELVING CARRIAGE Filed April 26, 196? Sheet 2 ATTORNEY UnitedStates Patent 8 Claims ABSTRACT OF THE DISCLOSURE A carriage to providerolling support for shelving or cabinet units of movable-stack type. Thecarriage is a rectangular angle-iron frame whose cross-members carryload and guide wheels arranged to run along the rectangular rails. Thecabinet or shelving rests on top of the carriage and has a handle on oneend panel for manually rolling the cabinet or shelving unit along therails.

This invention relates to a carriage to provide rolling support for acabinet or shelving unit of the mobile type. Such units are used inlibraries, oflices, and storage rooms in order to conserve space,particularly for dead storage or other situations where access isrequired relatively infrequently. The units can be stacked abutting faceto face, except for a single aisle space. When access is desired at aparticular location along the shelves, the unit or units beyond thedesired access aisle are merely rolled away, opening the aisle at thedesired location. In order that the units may be kept in alignment asthey are rolled back and forth it is generally convenient to support theunits on rails or tracks set on or in the floor.

Mobile shelving units for a library, file or storage room may typicallybe 8, 10, 12 feet or more in width, 7 to 8 feet in height, and up to 3feet in double-compartment depth. Manifestly such a unit will beextremely heavy when fully loaded with books, files, apparatus, ormachine parts stored therein. For the sake of economy, and to minimizeproblems of alignment and guidance, it is desirable to employ as fewload wheels as possible, usually 4 to 6, according to the width of theunit. This necessitates accommodating substantial concentrations of loadat the wheel attachments.

Various designs have heretofore been proposed for mobile shelving,generally involving special shelving-base construction in order toprovide for mounting the load wheels and guidance means. The usualpractice in prior units has been to provide the cabinets or shelvingunits with a modified, reinforced base frame for mounting the loadwheels and guidance devices. Despite rather elaborate and costly sucharrangements, prior units have generally been susceptible to sagging andbuckling effects, due to load concentrations at the wheel mounts, suchas to cause excessive friction, binding, or other conditions whichresult in excessive drag, particularly with large, heavily loaded units,to the extent of precluding manual locomotion within the capabilities ofa single attendant, often female. Therefore, prior designers haveresorted to power propulsion means, with the necessary drives, controls,and other expensive, elaborate provisions, which often involve firstcost and maintenance expense beyond the reach of many prospective users.The couplings, drives and operating mechanisms also require considerablespace, usually involving a sacrifice of the storage space itself, orcostly special floor construction to accommodate the several mechanisms.

It is an object of this invention to provide a mobile shelving carriagewhich will accommodate and support heavy shelf units in position forfree rolling along tracks or rails, which yet is light, compact,inexpensive to manu- 3,427,085 Patented Feb. 11, 1969 facture, andrequires little maintenance or operatin expense.

It is a further object of this invention to provide a carriage affordingadequate mobile support for a shelf unit of size, style, andconstruction substantially suitable for comparable shelving unitsfree-standing in stationary position on a floor.

It is still a further object of this invention to provide a mobileshelving carriage which includes simple, inexpensive mountingarrangements for load and guide wheels of conventional and readilyavailable types and sizes.

Another object of this invention is to provide, in association with amobile shelving carriage, a load wheel and guidance arrangement whichcan be used with a simple rectangular track, all so constructed andarranged that special floor construction is obviated, yet Withoutsignificantly sacrificing storage space.

Other objects and advantages of the invention will be apparent from theensuing description read in association with the accompanying drawings,wherein:

FIG. 1 is a perspective view of a mobile shelving stack, units of whichare equipped with carriages according to this invention;

FIG. 2 is a top plan view of the novel carriage of this invention inposition on the rails;

FIG. 3 is a side view of one corner of the carriage taken on line 3-3 ofFIG. 2, showing the load and guide Wheels and mounting thereof on thecarriage frame;

FIG. 4 is a bottom plan view of the carriage corner portion shown inFIG. 3, taken on line 44 of FIG. 3; and

FIG. 5 is a detail of a load-wheel axle.

Referring first to FIG. 1, reference numeral 10 indicates a mobile shelfunit having an end panel 11 with a handle 12 fastened to the panel.Three such shelving units are shown in the view, but obviously anynumber of such units may comprise a stack series, according to the spaceavailable. While the drawings show mobile units of identical size, aseries may include units of various depths, in such arrangement asprovides the maximum usable storage space in the given room. Forexample, a library storage room may house some sets of large books andsets of small books, the former of which may require deep shelf unitswhile the latter only requires shallow units. In any case, the seriescan be arranged in such multiples as to best utilize'the space alloted.

Units 13, 14 are single depth stationary units, or caps, which may beused to close the stack against the walls or other boundary lines. Forthe sake of convenience and appearance, the closure units 13, 14 arepreferably of the same general design as the mobile units 10, providingan additional complete storage unit on each end aisle. For long stacksit may be desirable to include a double depth stationary unit at thecenter of the stack and provide for two aisles, thus reducing the numberof mobile units which must be rolled to open terminal aisles.

The construction of the novel carriage is best seen in FIGS. 2, 3, and4. From FIG. 2 it will be seen that the carriage frame comprises a pairof parallel, spaced sill members '15, 16 tied at each end with a spacedpair of cross-members 17, 18 at the left end and 19, 20 at the rightend, the cross-members nesting in the sill angles. The lengths of thesill members 15, 16 are substantially equal to the base width of theshelving or cabinet unit to be supported and the members are so spacedthat the horizontal flanges 21, 22. of sill members 15, 16 underlie thebase framing of the cabinet or shelving unit providing full widthsupport. While various structural shapes or combinations thereof may beused to construct the frame, the drawings show a preferred form, inwhich all the members are made of the same angle-iron section, a typicalselection of which for average loading would be 1% x 1% x 3 angle. Asbest seen in FIGS. 2 and 4, sill flanges 21 and 22 overlie verticalcross-member flanges 23, 24, 25 and 26. The pieces are welded togetherat the corners formed by the flange intersects, as best seen at 27, 28in FIG. 3 and 29, 30 in FIG. 4.

-For very wide, heavy units of to 12 feet or more in width, it willusually be desirable to incorporate intermediate cross-members 31, 32,FIG. 2, in the carriage, to minimize sag and keep stresses in wheels andmountings within safe limits, without increasing the overall height ofthe carriage, thus permitting maximum utilization of basic framematerials and components.

'Each pair of cross-members 17, 18 and 19, is spaced apart, the spanbetween the spaces being equal to the span between rails 33 and 34. Aload wheel 35 is supported between cross-members at or near each cornerof the carriage, the arrangement being best seen in FIG. 3, which isillustrative of all wheel locations.

The space between vertical flanges 25, 26 of the cross angles is justslightly greater than the width of rail 34. The load-wheel rim width isabout the same as the width of rail 34, thus providing full widthload-bearing contact. Load wheel 35 is mounted on a fixed axle 36extending between flanges and 26. The axle 36 may conveniently be amodified cap screw, as seen in FIG. 5, having a head 37, a journal 38,and threaded end 39, the journal 38 having a length approximately equalto the width of the wheel journalled thereon.

Referring now to FIGS. 3 and 4, the guide wheels 40 and 41 depend fromhorizontal flanges 42 and 43 in position with their rims separated justslightly more than the width of rail 34. Guide wheels 40 and 41 arejournalled on fixed axles 44 and 45, similar to the load wheel axle 36,except having a shorter journal. The guide wheels are narrower than theload wheels, since the guide Wheels are called upon only to sustainhorizontal loading, which is generally nominal in value. Where necessaryfor assembly clearance purposes, as in the particular example hereshown, guide wheels 40 and 41 may be inset slightly from load wheel axle36, along flanges 42 and 43, obviating interferences, as for examplebetween heads and ends. However, as a general rule, the guide wheels arepositioned as near the outer ends of the cross-members 19 and 20 aspracticable, to provide the greatest guidance span cross-wise of thecarriage and thus to minimize weaving of the unit as it is rolled alongthe rails.

As seen in FIG. 3, rail 34 may be of solid rectangular cross-section,made of hardwood, for example, with a steel facing 46 across the top toserve as bearing surface for the load wheels and steel side facings 47and 48 opposed to the guide wheels.

For the sake of maximum efficiency, convenience, and economy, ball orroller bearing machine units are used for both the load and guidewheels. Where carriage assemblies are to be made in relatively smallquantities at any one time, a single size and style of machine unit maybe used for the wheels throughout. As shown, single hearing machineunits serve for the guide wheels 40 and 41, while two bearing machineunits 350, face to face, constitute load wheels 3-5, providing thenecessary rim width and radial-load bearing capacity for this service.For average service conditions, a bearing machine unit of 1 /2" OD. x A"face is suitable. Where large quantities of identical or closely similarmobile units are to be manufactured at one time, economy of suchmanufacture may dictate selection of wheels specifically sized for theparticular load conditions, without regard to interchangeability, forexample by using suitable double width hearing machine units, or thelike, as load wheels.

Assembly of the carriage and cabinet or shelving unit can usually bestbe done upon installation. The tracks 33, 34 are laid on the floor andthe carriage positioned on the rails, while the rails are temporarilyfixed, the carriage being then run back and forth, to check straightnessand parallelism of the rails. When rail positions are thus verified, therails may be permanently fastened down. The cabinet or shelf unit isthen set in position on the carriage, whose sills are provided withholes 49, FIG. 2, to receive cap screws or self-tapping screws 50,passing through the bottom rail 51 of unit 10, FIG. 1, to precludeshifting or tipping of the cabinet or shelf unit when being moved. Theremainder of the carriages and cabinets or shelf units are thenassembled in like manner in their respective positions on the rails,completing the installation. It will be seen that by virtue of thecarriages being self-contained units, assembly and installation areconsiderably simplified, as compared with prior designs, in which thecarriage is virtually an integral part of the unit. Furthermore, thecarriage, having a steel framework, is not subject to the warpage,sagging or buckling and consequent drag to which conventionally builtmobile shelving units are generally susceptible, particularly woodenones. Units made according to this invention remain free rolling underheavy loads with minimum maintenance. Permanently greased wheel bearingsmay be used, so that the installation will usually be maintenance free.With mobile unit stacks constructed according to this invention, one ormore large heavy units can easily be rolled by one female attendant oruser, thus facilitating access to any section of the stacks by personsusually attending or using same. For example, with the stack in theposition of FIG. 1, it will usually be feasible for the attendant toroll all three units 10 forward to open the rearmost aisle for access inthat section of the stack.

While I have described one form of the invention for the purpose ofillustration, it will be understood that those skilled in the art willbe enabled thereby to design modifications and variations of theinvention without departing from the spirit and scope of the appendedclaims.

What I claim and desire to secure by Letters Patent 1. A carriage for amobile shelving unit, comprising: a frame having a pair of structuralmetal sills and at least two pairs of structural metal cross-members,one pair of said cross-members being fixed transversely of said sillsnear each end thereof, load wheels supported upon said cross-membersnear the corners of said frame, said load wheels being journalled onhorizontal axles, and guide wheels suspended from said frame, said guidewheels being journalled on vertical axles, said carriage being fullyself-contained, whereby to sustain loads imposed by the weight of saidunit at said load wheels independently of said unit, when said unit issupported on said carriage.

2. A carriage according to claim 1, wherein said sills and saidcross-members consist of angle, ends of said cross-members being nestedin the angles of said sills.

3. A carriage according to claim 1, wherein the individual cross-membersof each end pair are spaced from each other, said load wheels beingbetween said individual members.

4. A carriage for a mobile shelving unit, or the like, comprising: aframe having a pair of structural metal sills and at least two pairs ofstructural metal cross-members, one pair of said cross-members beingfixed trans versely of said sills near each end thereof, load wheelssupported upon said cross-members near the corners of said frame, saidload wheels being journalled on horizontal axles, and guide wheelssuspended from said frame, said guide wheels being journalled onvertical axles, said sills and said cross-members consisting of angles,ends of said cross-members being nested in the angles of said sills, theindividual cross-members of each pair being spaced from each other, saidload wheels being between said individual members, said individualcross-members further being structural angles, each said individualcrossmember having a vertical leg and a horizontal leg, said load wheelsbeing supported upon opposed verh'cal legs, said guide wheels beingsuspended from said horizontal legs.

5. A carriage according to claim 4, wherein one of said load Wheels islocated near each corner of said frame, a pair of said guide wheelsbeing adjacent to each said load wheel, the guide wheels of each saidpair being spaced along said frame on opposite sides of an adjacent loadWheel.

6. A carriage according to claim 4, wherein said load wheel axles extendbetween said opposed vertical legs of said cross-members.

7. A carriage according to claim 2, further including receptor means onsaid sills adapted for aflixing said unit upon said carriage.

8. A carriage according to claim 7, wherein outline dimensions of saidcarriage are substantially the same as outline dimensions of said unitto 'be supported upon said carriage.

References Cited UNITED STATES PATENTS 206,416 7/1878 Bowman 1041191,501,060 7/1924 Miller 104247 3,080,204 3/1963 Lindhgren 3 l2--1993,095,828 7/1963 Deller 104-119 X 10 CASMIR A. NUNBERG, PrimaryExaminer.

US. Cl. X.R.

